Getting hired to shoot a wedding means your clients are trusting you to capture one of the most important days of their lives (no pressure or anything). When I was starting out as a wedding photographer, I was freaked out about not having everything I needed on hand. What if I had an equipment meltdown? What if the light was horrendous? When it comes to weddings, the what-ifs are endless. Preparation is your best friend.

Being the organized photographer that I am, I made a list of all the essential equipment . Over the years, I’ve added things to the list and taken things off as I developed a better sense of what’s truly vital. The list lets me focus on the important stuff, never forget anything, and get the job done without breaking my back lugging gear I don’t need.

You can use this list as your packing guide next time you’re preparing to shoot a wedding, and eventually you might find yourself adding and subtracting as your needs evolve — just like I did.

1. Camera and a Spare

I usually bring three cameras so I can shoot with two and have one as a backup, but I think two would get the job done. It’s essential to have an extra in case something goes wrong with your primary camera — and there are so many things that can go wrong. Live by this mantra: The most important equipment is your backup equipment!

2. Medium Zoom Lens

I use a 24-70 f2.8 lens as my medium zoom, and it’s the lens that I keep on my camera most of the time. This focal length is great for wedding portraits and photojournalism, offering both wide and tight perspectives. The pretty wide aperture gives me some flexibility in spaces that aren’t very well lit.

3. Telephoto Lens

You’ll need a longer lens to capture events from a distance, mainly the ceremony. I like to stand toward the back or sides so I’m not blocking anyone’s view. I take photos from that distance with my 70-200mm, and I also use that lens for closeups of the first dance.

4. Wide Angle Lens and Prime Lens

These are not as critical for a wedding, but certainly nice to have. The wide angle can get you shots of architectural details or big groups. The prime lens lets you shoot in dark spaces and gives you dreamy depth of field .

5. Speedlights

Using an external flash can be a lifesaver when you need a shot that’s just too dark to get otherwise. I have to use speedlight photography techniques for nighttime weddings and dark churches. The alternative is dark or grainy images.

6. Memory Cards and Batteries

Always bring more cards and batteries than you think you need. I’ll typically shoot 50 to 60 GB of images for a wedding and go through two sets of batteries per camera and per speedlight . Make sure the batteries are all charged up in advance.

7. Tripod and Light Stands

A good tripod will save you if you’re low on light and just need a little more stability. It’s also helpful if you’re working in very low light or compositing images together. The light stands come in handy too: You can put your speedlights on them, and they allow you to adjust the placement of the lights. Shoot-through umbrellas are also useful with the lightstands and speedlights when you’re doing portrait work.

8. Flash Diffuser

I like to bring a Gary Fong Lightsphere to put on top of my flash. It helps diffuse the light and makes for better portraits on the fly when there’s no time to set up lights.

9. Camera Bag

You’ll need a bag for all that gear. Make sure it’s roomy and comfortable enough to haul around with you as you’re moving throughout the day.

10. Studio Strobes and Umbrellas

Some photographers won’t agree with me that these are essential, but I like to have powerful strobes (more power than speedlights) to use on formal portraits in case I need them. Sometimes it rains or it’s too cold to take outdoor formals at a wedding, so I’m forced to take them inside, often in a dark church. When that happens, I like to have the speed and power of strobes to evenly light up a large group of people.

11. Lens Cleaning Kit and Lens Hoods

There’s a solid chance your lens will get dirty or wet as you’re shooting a fast-moving event, so it’s smart to keep a cleaning kit or lens wipes on hand to prevent smudges from ruining your shots. Lens hoods are a good way to avoid getting your lenses dirty in the first place, and they also help keep sun flare down.

Last tip before you go on your way: Make sure you always keep your lenses and equipment clean and well-maintained. Then you’ll be in excellent shape (not to mention panic-free) the next time you’re tapped to shoot an event-of-a-lifetime.